Tobacco sucker control

ABSTRACT

The control of undesirable secondary growth in plants is accomplished by applying thereto a composition comprising (1) Nalkyl acetamide having the formula:   WHEREIN R1 and R2 are independently hydrogen, methyl, alicyclic or acyclic alkyl groups having from 6 to 15 carbon atoms, with the total number of carbons in R1 and R2 being from 6 to 18; or the strong mineral acid salt of the N-alkyl acetamide; and (2) a surface active agent.

United States Patent [1 1 Abramitis 1 June 10, 1975 TOBACCO SUCKERCONTROL [75] Inventor: Walter W. Abramitis, Downers Grove, 11].

[73] Assignee: Akzona Incorporated, Asheville,

[22] Filed: Apr. 5, 1973 21 Appl. No.2 348,391

[52] US. Cl.. 71/78; 71/86;l03;118;122; 260/561 R OTHER PUBLICATIONSMcCutcheon, Detergents & Emulsifiers, 1966 Annual, p. 40, (1966).

Naege1i et al., A Modified Curtius Degradation etc.; (1929), CA 23, pp.2418-19, (1929). Gertler et al., Screening Tests of Some N-subs.Acetamides, etc; (1955), CA 50, pp. 7111-12, (1956). DeVilliers et al.,Structure and Activity in Molluscicides, (1967), CA 66, no. 114903q,(1967).

Primary Examiner-Glennon H. Hollrah Attorney, Agent, or FirmFrancis W.Young; Jack H. Hall; Hugo E. Weisberger [57] ABSTRACT The control ofundesirable secondary growth in plants is accomplished by applyingthereto a composition comprising (1) N-alkyl acetamide having theformula:

wherein R and R are independently hydrogen, methyl, alicyclic or acyclicalkyl groups having from 6 to 15 carbon atoms, with the total number ofcarbons in R and R being from 6 to 18; or the strong mineral acid saltof the N-alkyl acetamide; and (2) a surface active agent.

8 Claims, N0 Drawings TOBACCO SUCKER CONTROL BACKGROUND OF THE INVENTIONRelevant prior art is disclosed in U.S. Pat. Nos. 3,458,304, 3,619,165;3,506,433; and 3,663,629.

In various plants, such as, for example, tobacco, tomato, cotton,soybean plants, etc., undesirable secondary growth, which is generallyreferred to as suckers," creates a serious problem because the suckersdevelop rapidly to shade desired portions of the plant, compete fornutrients, and tends to lower the quality of such desired portions. Inthe tobacco plant, secondary buds form at the points where the leafstems join the plant, and later after the flower is removed grow rapidlyto form sucker growths extending over the leaves. The sucker growths canbe removed manually, but this is a laborious and expensive proceeding.The use of sucker oil and chemicals, while effective in control of suchsecondary growth, nevertheless have in the past had seriousdisadvantages. The sucker oil tends to form leaf and stalk damage,causing soft spots that are attacked by microbes, and also there is alack of control of the lower sucker stalks. The chemicals which havepreviously been used produce cellular changes in the leaf, tending toreduce the filling capacity of the treated tobacco for cigarettemanufacture. Further, the cost of the chemicals has been high.

DESCRIPTION OF THE INVENTION The composition of the invention, which isapplied to plants to avoid the above disadvantages, comprises an N-alkylacetamide and a surface active agent. The acetamide has the formula:

wherein R, and R are independently hydrogen, methyl, alicyclic, oracyclic alkyl groups having from 6 to carbon atoms, with the totalnumber of carbons in R and R being from 6 to 18. Additionally, byprotonation of the disubstituted amido groups, salts of strong mineralacids may be formed. Such salts include, for example, the hydrohalide,(e.g., hydrochloride), phosphate and sulfate.

The second component of the composition is a surface active agent oremulsifier which serves in providing uniform dispersions of allformulation components of both solid and liquid types, and may beanionic, cationic, or non-ionic, and includes conventional soaps, suchas the water-soluble salts of long chain carboxylic acids, the aminesoaps such as the amine salts of long chain carboxylic acids, thesulfonated animal, vegetable, and mineral oils, quaternary salts of highmolecular weight acids, rosin soaps such as salts of abietic acid,sulfuric acid salts of high molecular weight organic bases, algin soaps,ethylene oxide condensed with fatty acids and/or sorbitol esters, alkylphenols and mercaptans, and other simple as well as polymericcompositions having both hydrophilic and hydrophobic functions so as toenable the mixing of otherwise immiscible ingredients. Generally, thesurface active agents will be only a minor portion of the formulation asused, for example, less than 10 percent and frequently as low as 0.05percent. In general, concentrations of from 0.5 to

5% are found to be optimum. Typical useful emulsifiers by trade name andchemical description are as follows: Antarox A- 401,alkylarylpolyoxyethyleneglycol ether; Nonisol 2l0, polyethyleneglycolOleate; Triton X45, alkylarylpolyetheralcohol; polyoxyethylenecondensates of sorbitan fatty acids, e.g., Tween 20, Tween 60; and fattyacid esters of polyethylene glycol, e.g., Ethofat 60/25 and KesscoPEG-600 monostearatc.

Acetamides suitable for preparation of compositions of this inventioninclude those wherein R and R are aliphatic or cycloaliphatic groups,and are exemplified as follows.

N-undecylacetamide Mixtures of hexyl and heptyl straight chain N-alkylacetamides N-methyl-N-dodecylacetamide N-cyclohexyl acetamideN,N-dicyclohexyl acetamide N-pentadecyl acetamideN-methyl-N-dodecylacetamide hydrochloride N-cyclohexylacetamide'hydrochloride N,N-dicyclohexylacetamide sulfateN-cyclodecylacetamide N-cyclododecylacetamide The compounds of theinvention may be used for killing meristematic buds on ornamental andagricultural herbaceous, semiwoody, and woody plants such aschrysanthemum, cotton, azalea, apple, and tobacco. Meristematic budsinclude both terminal and axillary buds. The selective killing ofterminal buds is an application for which the chemicals of the inventionare particularly useful.

The chemicals of the present invention may be applied to plants, whichterm includes various plant parts such as flowers, fruits, vegetables,roots, and foliage in various manners. In one embodiment of theinvention, the composition is applied as an aqueous dispersion oremulsion. For example, the composition may be applied in a coarse waterspray directed to the stem of the plant, and such spray application isfound to give effective control. The chemicals may also be dissolved inorganic solvents such as acetone, benzene, or kerosene (assuming thesechemicals will not harm the plant), and the solutions of the chemicalscan be emulsified in water with the aid of surface-active agents. Thechemicals of the invention may be admixed with powdered solid carriers,such as mineral silicates, together with a surface-active agent so thata wettable powder may be obtained which may be applied directly toplants, or which may be shaken up with water for application to theplants in that form.

On a weight basis, the concentration of acetamide in the usefulformulations (before dilution with water or other materials prior toapplication) may vary widely, e.g., from 10 to Following dilution toform an aqueous formulation, the concentration of the acetamide is fromabout 0.01 to 10%, which is effective for the control of undesirablesecondary growth, and best results have been obtained usingconcentrations of from about 0.05 to 4%.

In the killing of meristematic tissue, a particularly advantageousembodiment of the invention is the use of an aliphatic alcohol incombination with the other chemicals of the composition. The resultingcompositions exhibit reduced phytotoxicity and good control ofmeristematic tissue while using lower concentrations of activeingredients. The amount of alcohol employed,

based on the combined weight of the acetamide, surface active agent, andalcohol is from 40 to 80%.

Alcohols useful in the preparation of the compositions of this inventioninclude hexanol. octanol, nonanol, decanol, undecanol, dodecanol, andmixtures thereof typified by commercially available products such asAlfo 810" sold by Continental Oil Company, which is a mixture ofoctanols and decanols. Other useful alcohols are exemplified by mixtures(C C C of alcohols sold under the designation of x0 alcohols by theMonsanto Chemical Company. These alcohol mixtures contain, for example,about 30% branched chain compounds which are generally 2-methylsubstituted alcohols. Suitable C C C mixtures contain, for example,about 40% C 40% C and 20% C The alcohols employed include both straightand branchedchain alcohols and can be derived from synthetic or naturalsources, e.g., paraffin and/or fatty acid esters. As employed in theinvention, the alcohols contain from 6 to 12 carbon atoms and preferablycontain from 8 to l 1 carbon atoms. It is understood that small amountsof impurities such as fatty acids and hydrocarbons will be present dueto the method of preparation of the alcohols employed, but this isgenerally undesirable and should be minimized where possible. Also,alcohols having less than 6 and more than 12 carbon atoms can be usedwith some benefit and indeed are frequently present as impurities.Suitable fatty acid sources for alcohols include caproic acid, caprylicacid, capric acid, and lauric acid and their corresponding esters withthe alcohol being produced by reduction of the acid or ester by meanswell known in the art.

The acetamides employed in the invention may be prepared by the usualmethods of amide formation. Several examples are set forth below.

EXAMPLE A This example illustrates the preparation of a C acetamidepossessing tobacco suckering action. Two moles of a C aliphatic aminehaving amino groups distributed on internal carbon atoms was reactedwith five moles of acetic anhydride at 20 30 C. for about 18 hours. Thereaction product was admixed with water and the organic portion wasextracted with petroleum ether, washed with water and dilute caustic,and placed over Na SO overnight to dry. The petroleum ether wassubsequently stripped off using aspirator pressure and the product wasfurther dried with benzene. The product analysis revealed 94.8% amideand 0.02% water. The yield was 94.6%.

EXAMPLE B This example illustrates the preparation of N,N-

dicyclohexyl acetamide by reacting equal molar amounts of aceticanhydride and dicyclohexyl amine. By-product acetic acid was removed bydistillation and the residue was added to 500 cc. of petroleum etherfrom which the product quickly crystallized out.

EXAMPLE C This example illustrates the preparation of cyclododecylacetamide by reacting one mole of cyclododecyl amine with 1.1 mole ofacetic anhydride in the presence of benzene. The solid product wasdissolved in hot benzene and was recrystallized to yield 215.5 grams ofproduct analyzed as essentially 100% amide having a melting point of141-l42C.

EXAMPLE D The following-examples illustrate the application ofcompositions of the invention to tobacco plants. As applied, thecompositions were in the form of aqueous emulsions. These were appliedto tabacco plants in the early button to early flowering stages, byspraying with a 3-nozzle sprayer and allowing the emulsion to drain downalong the stem of the plant where meristematic and differentiatingtissues are destroyed through contact. The emulsions were applied at arate of approximately 30 to 50 gallons per acre.

After 9 days, the effectiveness of the spraytreatment was determined byweighing the number of suckers remaining after treatment and comparingwith the weight of suckers present in a control plot wherein the tobaccowas untreated. The degree of sucker control was then expressed as thepercentage formed by suckers from the treated plot as compared withsuckers in the control plot, e.g., if the total weight of suckers fromthe treated plot was 25 percent less than the total sucker weight fromthe control plot, the degree of sucker control was 25 percent.

Attention was also given to the degree of plant injury accompanyingapplication of the sucker-control agents of the invention. Injury wasdetermined by visual estimate. Slight injury means that visualobservation indicated only occasional necrotic light spotting on foliageof less than 5 percent of the plants. Light injury was spotting orbrowning on 5 20 percent of the plants. Moderate injury was roughly 20to 50 percent spotting or browning, and heavy damage was considered tobe anything in excess of 50 percent.

The results of the applications as described above are set forth in theTable.

TABLE Sucker Example Composition Act. Ingredients Control Plant InjuryType of Tobacco Conc. Soln. (after 9 days) 1 C C, alkyl acetamide 1.0%1.0 25 None Flue-cured lsopropyl alcohol** 5.0% Sorbitan Ester 2.0%Water 92.0%

2 C alkyl acetamide 20.0% 2.0 100 *:95 None zNone Burley C C alkylalcohol 75.0% 1.0 100 *195 None*:None Burley Sorbitan Ester 5.0% 0.5None*:None Burley 3 C alkyl acetamide 20.0% 2.0 None Burley C C alkylalcohol 750% 1.0 50 None Burley Sorbitan Ester 5.0% 0.5 10 None Burley 4N-methyl-N-dodecylacetamide l .0% 1.0 100 Moderate Flue-cured SorbitanEster 2.0% 0.5 98 Light Flue-cured Water 97.0% 0.25 90 *zl00 SlightzNone flue-cured TABLE Contmued Sucker Ex l C itio Act. IngredientsControl Plant Injury Type of Tobacco Conc. Soln. (after 9 days) 5N-methyl-N-dodecylacetamide 20.0% 2.0 90 Moderate Burley C C alkylalcohol 75.0% 1.0 100 None Burley Sorbitan Ester 5.0% 0.5 100 *290None*None Burley 2.5 90 None Cigar 1.25 70 None Cigar *24 hour readingon primary suckers 6 N-methyl-N-dodecylacetamide 20.0% 4.0 100 ModerateBurley C C alkyl alcohol 60.0% 2.0 98 Moderate Burley Sorbitan Ester20.0% 1.0 80 Slight Burley 7 Cyclohexylacetatnide l .0% 1.0 100 NoneFlue-cured lsopropyl alcohol** 5.0% Sorbitan Ester 2.0% Water 92.0%

8 Dicyclohexylacetamide 1.0% 1.0 l None Flue-cured Isopropyl alcohol**5.0% Sorbitan Ester 2.0% Water 92.0%

9 Cyclododecylacetamide 10.0% I0 100 *2100 None*:None Burley C C alkylalcohol 35.5% 0.5 95 *:0 None*:None Burley Sorbitan Ester 2.5% lsopropylalcohol** 50.0%

Indicates that degree of sucker control was estimated after 24 hoursrather than 9 days. "In runs l. 7 9, isopropyl alcohol was employed tosolubilize the acetamide and is not believed to be the activeingredient.

In the ab a p the ita ester pl y d 25 in which R is selected from thegroup consisting of hyas an emulsifier was a condensation product ofapproximately equal molar amounts of sorbitol and coconut fatty acid andabout 20 moles of ethylene oxide. Such esters are widely available on acommerical basis, e.g., Armak Company sells this sorbitan ester asArmotan PML-20.

The C C alkyl alcohol employed in a number of the examples is availablecommerically as Alfo 810, a product of the Continental Oil Company.

Comparison of example 4 with examples and 6 demonstrates the use of theacetamide alone (example 4) in contrast with a combination of theacetamide with the C C alkyl alcohol. From example 4, it can be seenthat the use of the acetamide alone results in acceptable suckeringaction. It should also be noted that the level of suckering action isalso related to the amount of acetamide employed, i.e., as theconcentration (as applied to the plants) is reduced, suckering actionmay vary. With regard to examples 1 and 8, only slight suckering actionwas achieved. However, once it is known that the acetamides possesstobacco suckering action, the concentration of the acetamide can beadjusted to produce the desired results.

What is claimed is:

1. Composition for controlling the growth of suckers in tobacco plants.consisting essentially of:

a. from about to about 75 percent by weight of a member of the groupconsisting of an N-substituted acetamide of the formula:

CH3 C K 1 drogen, methyl, and cyclohexyl; R is selected from the groupconsisting of alkyl having 6 to 15 carbon atoms, cyclohexyl, andcyclododecyl; and the soluble mineral acid salts thereof selected fromthe group consisting of the hydrochloride, phosphate and sulfate;

b. from about 0.05 to about 10 percent by weight of a surface activeagent; and

c. from about 40 to about percent of the total weight of the compositionof an alkanol having 6 to 12 carbon atoms.

2. The composition of claim 1 in which the acetamide is N,N-dicyclohexylacetamide.

3. A composition as in claim 1 wherein the acetamide isN-undecylacetamide.

4. A composition as in claim 1 wherein the acetamide isN-methyl-N-dodecylacetamide.

5. A composition as in claim 1 wherein the acetamide is N-cyclohexylacetamide.

6. A composition as in claim 1 wherein the surface active agent is asorbitol lauric acid ester of polyethylene glycol containing about 20ethoxy moieties per molecule. v

7. The composition of claim 1 in the form of an aque ous dispersion inwhich the concentration of the N- substituted acetamide is between about0.25 and about 10 percent by weight.

8. Method for controlling suckers in tobacco plants which comprisesapplying to a tobacco plant an amount of the composition of claim 1effective to inhibit the growth of suckers thereon.

1. COMPOSITION FOR CONTROLLING THE GROWTH OF SUCKERS IN TOBACCO PLANTS,CONSISTING ESSENTIALLY OF: A. FROM ABOUT 10 TO ABOUT 75 PERCENT BYWEIGHT OF A MEMEBER OF THE GROUP CONSISTING OF AN N-SUBSTITUTEDACETAMIDE OF THE FORMULA:
 2. The composition of claim 1 in which theacetamide is N,N-dicyclohexyl acetamide.
 3. A composition as in claim 1wherein the acetamide is N-undecylacetamide.
 4. A composition as inclaim 1 wherein the acetamide is N-methyl-N-dodecylacetamide.
 5. Acomposition as in claim 1 wherein the acetamide is N-cyclohexylacetamide.
 6. A composition as in claim 1 wherein the surface activeagent is a sorbitol lauric acid ester of polyethylene glycol containingabout 20 ethoxy moieties per molecule.
 7. The composition of claim 1 inthe form of an aqueous dispersion in which the concentration of theN-substituted acetamide is between about 0.25 and about 10 percent byweight.
 8. Method for controlling suckers in tobacco plants whichcomprises applying to a tobacco plant an amount of the composition ofclaim 1 effective to inhibit the growth of suckers thereon.